diff --git a/common/modules/mixly-modules/web/ampy.js b/common/modules/mixly-modules/web/ampy.js
index db348eac..42de7be1 100644
--- a/common/modules/mixly-modules/web/ampy.js
+++ b/common/modules/mixly-modules/web/ampy.js
@@ -237,8 +237,10 @@ class AmpyExt extends Ampy {
         }
         await this.exec(`file = open('${filename}', 'wb')`, timeout);
         let buffer = null;
-        if (typeof data === 'string') {
+        if (data.constructor === String) {
             buffer = this.#device_.encode(data);
+        } else if (data.constructor === ArrayBuffer) {
+            buffer = new Uint8Array(data);
         } else {
             buffer = data;
         }
@@ -255,7 +257,7 @@ class AmpyExt extends Ampy {
             }
             await this.exec(`file.write(b'${writeStr}')`, timeout);
         }
-        await this.exec(`file.close()`, timeout);
+        await this.exec('file.close()', timeout);
     }
 
     async ls(directory = '/', longFormat = true, recursive = false, timeout = 5000) {